#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int s = 1;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= i; j++) {
      cout << char('A' + s - 1);
      s++;
      if (s == 27)
        s = 1;
    }
    cout<<endl;
  }
  return 0;
}